Non-aqueous electrolyte batteries represented by lithium ion batteries are widely used as main power source and memory backup power source in various electronic devices. Particularly in recent years, the demand for non-aqueous electrolyte batteries shows an increasing trend year by year, with increase of small portable devices such as cellular phones, digital still cameras, and wireless communication devices. While the reduction in size and weight of the devices proceeds, more functionality and increase in memory capacity are required for the devices. Therefore, in applications such as main power source and memory backup power source, the batteries are required to be small in size and have a high capacity. In addition, in such applications, it is important to ensure excellent reliability over a long period of time.
With regard to the positive electrode active material of non-aqueous electrolyte batteries, for example, manganese dioxide and graphite fluoride are used in primary batteries; in secondary batteries, the use of sulfides such as TiS2 and MoS2, oxides such as manganese dioxide and vanadium pentoxide (V2O5), and lithium-containing transition metal composite oxides such as lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide is examined. Vanadium pentoxide can absorb and release lithium ion, and has a high theoretical capacity. Non-aqueous electrolyte batteries in which a positive electrode including vanadium pentoxide is combined with a lithium negative electrode, due to their small self-discharge, are used for backup and other purposes.
For example, Patent Literature 1 discloses using a positive electrode including vanadium pentoxide and aluminum powder, and a negative electrode including niobium pentoxide doped with lithium, in lithium secondary batteries used for backup or power supply to portable devices.